Abstract : In contrast to the situation in many European countries, the mortality of immigrants in France has been little studied. The main reasons for the lack of studies are based on ethical and ideological considerations. The objective of this study is to explore mortality by country of birth in Metropolitan (i.e. 'mainland') France. Complete mortality data were used to study the relative risks of mortality of the foreign- and locally-born populations by gender, age and cause of death for the period 2004-2007 in Metropolitan France. Analyses were conducted by countries of birth grouped into geographic areas and by the Human Development Index (HDI). The differentials in mortality between foreign-born and locally-born populations were not homogeneous. The figures varied by age (higher foreign-born mortality for the young; lower mortality for migrants aged 15-64 years), gender (female migrants more frequently had higher relative mortality than men migrants), country of birth (Eastern European-born migrants had higher mortality, while those born in Morocco, Central Asia, 'other Asian countries' and America had lower mortality) and cause of death (migrant mortality was higher overall for deaths caused by infectious diseases and diabetes, and lower for violent death and neoplasm). Moreover, mortality relative risks for male, violent deaths and cancer were positively associated with country-of-birth HDI, while female mortality and infectious disease mortality were negatively associated with country-of-birth HDI. Some important caveats have to be considered because the study did not control for individuals socioeconomic position in France, or length of residence in the host country. A strong healthy migrant effect was suggested and its intensity varies with age and gender (which may reflect different reasons for migration). For some specific causes of death, a lifestyle effect seems to explain mortality differentials. The associations between HDI and mortality show that mortality trends are partly related to the educational, sanitary and economic conditions of the country of birth. Further studies would enrich the differential analysis of mortality by country of birth by contributing additional detailed data on socioeconomic and living conditions in the host country as well as in the country of origin.